This invention relates to apparatus for supporting a first tubular member within a second tubular member. The apparatus has particular application to drilling equipment where, for example, it is sometimes necessary to support a casing string within a wellhead.
During the formation of drilling installations, successive links of casing are run into a well through wellhead equipment. Situations can arise in which a casing string cannot be run to its full depth and becomes stuck. In such a situation it is necessary to suspend the casing string within the wellhead. This can be a problem with conventional equipment since a blowout preventer is usually located above the wellhead and, because of the presence of casing couplings it is not normally possible to gain access to the annular space between the wellhead and the casing without removal of the blowout preventer. This is undesirable.
The J. A. Haeber U.S. Pat. No. 3,098,525 discloses a running tool for running and retrieving a well casing hanger into and from an underwater well casinghead. The tool includes a piston operated latch to connect the casing hanger in the casinghead. A latching pin responds to the latch segments to hold slips in an inactive position until the running tool is released and then the slips move downward on the exterior of the casing hanger to engage the interior of the casing head because they are biased downwardly by springs.
The P. A. White U.S. Pat. No. 4,249,601 discloses a liner hanger running and setting tool which includes a hydraulic piston to transmit relative longitudinal movement to two movable tubular members to set the gripping slips which anchor the hanger in the well.
The A. G. Ahlstone U.S. Pat. No. 3,468,559 discloses the use of hydraulically set seal and packoff.
The E. M. Mouret et al U.S. Pat. No. 4,067,388 discloses a tool for running underwater casing hangers which has a resilient split ring to connect the tool to the hanger and utilizes hydraulics or rotation to disconnect the tool from the hanger.